Methods of Analysis
The majority of investigators interested in carrying out quantitation of bone biopsies count the cells within a certain area using a grid. The grid is placed in the eyepiece of the microscope and is projected onto the field at a magnification of about 100 times. The grid may be a series of points on a number of lines or it may consist of a cross-hatched area or merely an array of lines. If the grid is cross-hatched or if lines with points are used, it is most common to evaluate the event that is occurring at the grid intersections or at the point where the line crosses the bone surface to be analyzed. In a bone biopsy the presence of an osteoblast, of an osteoclast, or of an inactive surface are the three major events recorded. If enough events or hits are recorded to provide statistically valid results, the average number of events as a percentage of the total number of points is representative of the area of active cells as a fraction of the total area of the sample, which in turn reflects the section. Courpron, Merz, Bordier, Schultz, Sedlin, Teitelbaum, and Sherrard all utilize grids and point-count methods for evaluation of bone turnover (Courpron et al., 1974; Merz and Schenk, 1970; Bordier et al., 1964; Schultz and Delling, 1976a; Sedlin et al., 1963; Sherrard et al., 1974 and Teitelbaum et al., 1976a). The exception is Jowsey who evaluates what is occurring on all of the surface rather than a finite number of randomly selected samples of the surface (see below).
KeywordsBone Resorption Bone Turnover Bone Surface Bone Biopsy Grid Intersection
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